Water cooled container for hot working metal



a FIG.I 4

' KW '7 Y Jan. 2, 1968 D. A. EDGECOMBE 3,360,975

WATER COOLED CONTAINER FOR HOT WORKING METAL Filed D60. 16, 1965 w WWW W INVENTOR. David A. Edgecombe United States Patent 3,360,975 WATER COOLED CONTAINER FOR HOT WORKING METAL David A. Edgecombe, Beaver Falls, Pa., assignor to The Babcock & Wilcox Company, New York, N.Y., a corporation of New Jersey Filed Dec. 16, 1965, Ser. No. 514,266 8 Claims. (Cl. 72-272) The present invention relates to the hot working of metal, and more particularly to the use of pressure to squeeze-form hot metal in, for example, the extrusion process for shaping metal.

In the extrusion of ferrous alloys it is customary to con-fine a hot billet in a container with the metal being squeezed through a die at one end of the container to form a finished or semi-finished product. When the extrusion process is utilized in forming tubes the hot billet is delivered to the press with a centrally located bore or opening therethrough. The bore may be formed by drilling, or the like, prior to extrusion, but preferably is formed by piercing the billet by pressure while in a container.

Heretofore, the extrusion or piercing procedure includes a cleaning and cooling stage immediately preceding the insertion of the hot unpierced billet into the container. The cooling was previously accomplished by the use of a water spray contacting the inner surface of the container bore. Such a procedure was reasonably adequate for low tonnage rates for Working the metal, but increasing the tonnage of metal worked in a unit of time leads to difficulties in adequately cooling the container without subjecting the container metal to thermal shock and resultant cracking of the surface of the metal walls, which in turn leads to a shortened useful life of the container.

In accordance with the present invention I provide' an improved cooling arrangement involving the use of cooling fluid flow passageways formed in the annular walls of the container. The passageways are constructed and arranged for a controlled flow of fluid therethrough as may be necessary for proper cooling of the container. I have also found that it is desirable to form the fluid flow passageways so that the flow path of the fluid through the container is relatively short to avoid the creation of steam pockets in the passageways, which may lead to a restrictive or blockage of the fluid flow path. The cooling fluid flow passageways within the annular wall of the container are controlled as to the flow therethrough to maintain a desirable operating range of container metal temperatures to avoid excessive container metal temperature and thermal shock and to thus lengthen the useful life of the container metals.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and described a preferred embodiment of the invention.

Of the drawings:

FIG. 1 is a section, taken along the axis of an extrusion press container constructed and arranged according to the present invention; and

FIG. 2 is a view, on a reduced scale, taken on the line 2-2 of FIG. 1 with the cross-hatching removed to show the configuration of the cooling fluid flow passageways within the container.

The present invention is illustrated in the form of a container for the extrusion of tubes. It will be under- 'ice stood the container may also be used in the piercing of billets, and the container may be arranged with its bore axis either horizontal, as shown, or vertical.

As shown in the drawings, the container 10 is formed of a block of metal which may be of circular or square outside configuration, but will have a central bore formed Within the container. As shown, the machined inner surface 11 of the container is tapered to accommodate a liner holder 12 which is of generally uniform thickness tapering from one end to the other so as to fit within the machined surface 11 of the container 10.

A liner insert 13 is positioned within the liner holder 12 with its outer surface 14 tapered to conform with inner tapered surface 15 of the liner holder 12 and having its inner diameter or bore 16 substantially uniform throughout its length. The liner holder and liner are positioned within the container. The liner holder is held in position by a shrink fit within the container body and by a keeper plate 12A and a face plate 12B secured to the container body 10. The liner 13 is also retained in position by a shrink fit, aided by the die holder 17 which is backed by a die support 81 forming a part of the die carrier 20. The die 21 and its backing ring 22 are held within the end of the container so that the assembly will be maintained in the relative position shown in FIG. 1 during the extrusion operation.

A pierced billet 23 is inserted within the bore 16 of the liner insert 13 with, for example, a disk of glass lubricant (not shown) positioned between the inner end of the pierced billet 23 and the die 21. In the usual extrusion operation the exterior surface 24 of the billet as well as its inner bore 25 are coated with lubrication such as glass so as to permit extrusion of a finished tube 26 through the die 21 of the extrusion press.

The billet is press-formed by pressure imposed on the end of the billet by means of a piston 27 having a dummy head 28 in direct contact with the billet 23.

As shown, the piston 27 and its dummy head 28 are provided with a central opening 30 therein to accommodate a mandrel 31 which is inserted through the central bore 25 of the billet and the die 21 before pressure is applied to the billet. With pressure exerted through the dummy head 28 by the extrusion press the metal of the billet 23 is extruded through the die 21 to form the tube 26.

In the ordinary operation of an extrusion press completion of the extrusion of the billet leaves a discard of metal adjacent the die 21 which must be removed before the press is ready for the next succeeding extrusion cycle. Removal of the discard, cleaning of the bore of the com tainer liner 13 and preparation of the press for a repeat extrusion cycle is coordinated so that successive billets may be extruded at a rate in excess of extrusions per hour. In such a cycle of operations it is highly necessary to maintain the container 10, with its liner holder 12 and the liner insert 13, at a preferred temperature so that heat damage to the metal thereof will be minimized, while at the same time the temperature of the metal should not be too low so as to adversely influence the extrusion of the hot billet.

In accordance with the present invention, the container 10 is provided with circumferentially arranged axially spaced passageways or grooves 32 formed in the inner surface 11 of the container 10. The grooves'32 lie in axially spaced planes which are parallel to each other and substantially normal to the axis of the liner bore 16. As show-n in FIG. 2, each of the grooves 32 is provided with a generally radial inlet connection 33 or 34, a connection 33 terminating in fluid flow inlet passage 35 and connection 34 terminating in fluid flow inlet passage 36 for the admission of cooling fluid to the respective passageways.

The passageways are also provided with radial outlet connections 37 and 38 to outlet passages 40 and 41 respectively. The inlet and outlet passages for each passageway 32 are relatively closely spaced and each groove or passageway 32 extends through an angle of approximately 320 around the container inner surface 11.

Each of the inlet and outlet passages 35, 36, 3'7 and 38 are arranged substantially parallel to the axis of the bore 16 of the liner in the annular wall of the container. The admission of cooling fluid to the inlet passages 35 and 36 may be by means of a radial inlet connection 42 receiving cooling fluid from an external pump 43 as shown in FIG. 1, while each of the outlet passages 37 and 38 may be correspondingly provided with an outlet connection (not shown) arranged radially with respect to the axis of the container liner 13.

As shown in FIGS. 1 and 2 alternate passageways 32 are supplied by a connection to a common inlet passage and a common outlet passage. Thus fluid from fluid inlet 35 passes through inlet connection 33, into groove 32 and flows clockwise around the exterior of the liner holder 12, through outlet connection 37 and into outlet passage 40. The adjacent groove is arranged with a similar fluid flow path, with flow in the opposite direction, i.e., from fluid inlet 36, through inlet connection 34 into groove 32, thence counterclockwise to outlet connection 38 thence into outlet passage 41. With this arrangement the fluid flow cooling effect of alternate passageways overlap the space between inlet and outlet passages for the adjacent passageways.

In the embodiment shown the spacing between adjacent planes in which the grooves or passageways 32 are formed diminishes in going from the open to the die end of the container The groove spacing may diminish toward the die end as shown, may be equal throughout the length of the container, or conversely the spacing may diminish toward the open end of the container. When a container is used in piercing a billet the axial spacing between the passageways will ordinarily be equal. However, such spacing will be largely dependent upon the container and component design and to compensate for the likelihood of heat buildup within the wall of the container during the hot working cycle.

As shown in FIG. 1 a thermocouple 44 is imbedded in the wall of liner holder 12 between the inner surface of the container liner surface 16 and the passageways 32. As shown, the thermocouple is inserted in an aperture 45 extending to a position intermediate the length of the liner holder 12. The container 10 is radially machined to accommodate an armored cable 46 leading outwardly across one face of the container 10. Preferably the groove in the container in which the armored cable is inserted is protected by a metal plate 47 attached to the end face of the container 10.

Ordinarily a continuous flow of cooling fluid is not necessary through the passageways 32 of the container 10. The flow of cooling fluid as supplied by the pump 43 is therefore regulated in response to the temperature indication determined by means of the thermocouple 44, the operation of the pump will be intermittent between a flow condition corresponding to the maximum allowable metal temperature and a condition of no flow, when the pump is inoperative at lower metal temperatures. These conditions of pump operation may be either automatically or manually regulated by the use of the temperature indications of the thermocouple 44 by well-known control means.

The construction and arrangement shown has permitted an appreciable increase in the life of the container, the liner holder and the liner even when the extrusion press has been used for a high rate of billet extrusion. Operation has indicated that under the same operating rate the life of the container and its associated parts would be reduced to less than one-half that without the controlled cooling shown.

While in accordance with the provisions of the statutes I have illustrated and described herein the best form and mode of operation of the invention now known to me, those skilled in the art will understand that changes may be made in the form of the apparatus disclosed without departing from the spirit of the invention covered by my claims, and that certain features of my invention may sometimes be used to advantage without a corresponding use of other features.

What is claimed is:

1. In apparatus for working hot metal the combination comprising an annular wall defining a container having a central bore, means for restricting the opening at one end of said central bore, means for inserting a hot metal workpiece into the opposite end of said central bore, means for applying force on said workpiece through the opposite end of said central bore, and means for regulating the temperature of said container including means forming fluid flow passageways within the wall of said container, said passageways being disposed in separate planes substantially normal to the axis of and substantially uniformly spaced from the bore of said container, means for passing a flow of fluid separately through each of said passageways and means for controlling the flow of fluid through said passageways.

2. The combination according to claim 1 wherein said means for passing a flow of fluid separately through said passageways includes means forming inlet and outlet passages within the wall of said container communicating with each of said passageways.

3. The combination according to claim 1 wherein the spacing between said passageways decreases axially of said central bore toward the restricted end of the bore.

4. The combination according to claim 1 wherein each of said passageways has substantially the same cross-sectional flow area.

5. The combination according to claim 1 wherein each of said passageways connects with an inlet passage and an outlet passage on opposite sides of said container.

6. The combination according to claim 1 wherein said fluid flow controlling means includes a thermocouple positioned between the surface of said container bore and said fluid flow passageways.

7. The combination according to claim 1 wherein said container includes a liner holder and an interior liner defining the working bore of said container.

8. The combination according to claim 7 wherein the fluid flow passageways are positioned at the interface of the liner holder and the container.

References Cited UNITED STATES PATENTS 1,715,936 6/1929 Madden 72272 2,161,570 6/1939 Harris 72342 2,207,405 7/ 1940 Jacobson 72272 2,726,761 12/1955 Larsen 72272 CHARLES W. LANHAM, Primary Examiner.

H. D. HOINKES, Assistant Examiner. 

1. IN APPARATUS FOR WORKING HOT METAL THE COMBINATION COMPRISING AN ANNULAR WALL DEFINING A CONTAINER HAVING A CENTRAL BORE, MEANS FOR RESTRICTING THE OPENING AT ONE END OF SAID CENTRAL BORE, MEANS FOR INSERTING A HOT METAL WORKPIECE INTO THE OPPOSITE END OF SAID CENTRAL BORE, MEANS FOR APPLYING FORCE ON SAID WORKPIECE THROUTH THE OPPOSITE END OF SAID CENTRAL BORE, AND MEANS FOR REGULATING THE TEMPERATURE OF SAID CONTAINER INCLUDING MEANS FORMING FLUID FLOW PASSAGEWAYS WITHIN THE WALL OF SAID CONTAINER, SAID PASSAGEWAYS BEING DISPOSED IN SEPARATE PLANES SUBSTANTIALLY NORMAL TO THE AXIS OF AND SUBSTANTIALLY UNIFORMLY SPACED FROM THE BORE OF SAID CONTAINER, MEANS FOR PASSING A FLOW OF FLUID SEPARATELY THROUGH EACH OF SAID PASSAGEWAYS AND MEANS FOR CONTROLLING THE FLOW OF FLUIDS THROUGH SAID PASSAGEWAYS. 